U.S. Pat. No. 7,889,524 B2 discloses a power module for a hybrid electric vehicle with an integrated converter, which comprises a rectifier for converting AC voltage into DC voltage, a DC-DC voltage converter for converting a first voltage into a second voltage, and a battery for storing electric energy. The integrated converter operates in three modes: 1) AC charging mode, 2) boost mode for supplying power from the battery to the electric bus, and 3) buck mode for supplying power from the electric bus to the battery.